1. Field of the Invention
The present invention relates, in general, to a back-stop device for preventing reverse rotation of a rotor in fishing reels and, more particularly, to a backstop device comprising an inner race, consisting of a plurality of needle rollers individually kept in a roller seat opening, and a backstop body integrated with the inner race so as to prevent reverse rotation of a rotor and acting as an outer race of a one-way roller bearing, thus being free from any typical expensive and complicated outer race.
2. Description of the Prior Art
As well known to those skilled in the art, typical backstop devices, used for preventing reverse rotation of a rotor in fishing reels, include a one-way roller bearing and a backstop body. The typical backstop device including a one-way roller bearing and a backstop body is shown in FIGS. 1 and 2. The one-way roller bearing 3 of a typical backstop device includes two races: an inner race 1 and an outer race 2 which are assembled into a single body. The inner race 1 includes a cylindrical body 1a with a plurality of regularly spaced roller seat openings 1b. A needle roller 1d is rotatably held in each of the roller seat openings 1b by a roller holder 1e and is biased by a plate spring 1c installed on one side surface of each roller seat opening 1b.
The outer race 2 has to withstand a wedging effect of the needle rollers 1d, so the race 2 is preferably formed of a case hardened steel plate through a drawing process. That is, the outer race 2 is formed as a cylindrical body, closed at the bottom and has outward bulges at regularly spaced axial positions of the side wall, thus having a plurality of axially bulging portions 2a. Due to the axially bulging portions 2a, interior depressions 2b and sloped surfaces 2c are formed on the inner surface 2e of the outer race 2. The inner surface 2e of the outer race 2 is produced by a nitrification or corrosion-resistive process so as to improve anticorrosion properties. The inner lip of the outer race 2 extends slightly inward, thereby forming an annular collar 2d capable of preventing an unexpected separation of the inner race 1 from the outer race 2.
The backstop body 4 of a typical backstop device includes a cylindrical bearing receiver 4a which receives and holds the one-way roller bearing 3. The inner surface of the bearing receiver 4a is provided with a plurality of regularly spaced axially formed ridges 4c with a plurality of valleys 4b being formed between the ridges 4c, thus contacting the axially bulging outer surface of the outer race 2. A toothed ring 4e, with a plurality of stop grooves 4d, is exteriorly formed on one end of the bearing receiver 4a. In the above backstop device, the one-way roller bearing 3 and the backstop body 4 are separately produced prior to being assembled into a single body. The construction of an assembled backstop device is shown in a cross-sectioned view of FIG. 2 in detail.
In order to assemble the one-way roller bearing 3 and the backstop body 4 into a backstop device, the roller bearing 3 is fitted into the bearing receiver 4a of the backstop body 4 prior to being installed in a fishing reel.
FIGS. 3 and 4 are views showing the construction and operation of the typical backstop device installed in a fishing reel. As shown in the drawings, when a handle (not shown) of the reel is rotated with a predetermined direction by a user, the rotating force of the handle is transmitted to a helical gear 15 of a hollow drive shaft 10 through a drive gear 14, thus rotating the drive shaft 10 along with a sleeve 11.
When a control lever 13 is operated so as to bring a stopper 12 into engagement with one of the stop grooves 4d of the backstop body 4, the backstop body 4 is brought into a stop position where the body 4 is not rotatable. When the drive shaft 10 along with the sleeve 11 is rotated in a normal direction (clockwise in FIG. 3) at such a stop position of the backstop body 4, the needle rollers 1d interposed between the sloped surfaces 2c of the outer race 2 and the external surface of the sleeve 11, roll on the sleeve 11 in the normal direction. In such a case, each of the axially bulging portions 2a of the outer race 2 moves to one side of an associated valley 4b of the backstop body 4. Therefore, each of the needle rollers 1d shifts from the shallow portion of the sloped surface 2c to the interior depression 2b due to the frictional rotating force of the sleeve 11 being rotated toward the interior depressions 2b. The needle rollers 1d are thus positioned and smoothly rotated in the depressions 2b, thus allowing the rotor 16, mounted to the end of the drive shaft 10, to be freely rotated in the normal direction.
Meanwhile, when the drive shaft 10 along with the sleeve 11 is rotated in a reverse direction (clockwise in FIG. 3) at the stop position of the backstop body 4, the needle rollers 1d roll on the sleeve 11 in the reverse direction. In such a case, each of the axially bulging portions 2a of the outer race 2 moves to the other side of an associated valley 4b of the backstop body 4. Therefore, each of the needle rollers 1d shifts from the deep portion of the slopes surface 2c to the shallower portion thereof due to the frictional rotating force of the sleeve 11 being rotated toward the shallow portions of the slope surfaces 2c. The needle rollers 1d are thus wedged between the shallow portions of the sloped surfaces 2c and the outer surface of the sleeve 11, so both the backstop body 4 and the sleeve 11 are not rotatable. Therefore, the sleeve 11, the drive shaft 10, and the rotor 16 are all prevented from being rotated in the reverse direction.
However, the above backstop device has a problem caused by the one-way roller bearing and the backstop body which are separately produced prior to being assembled into a single body. That is, the roller bearing is fitted into the bearing receiver and integrated with the backstop body, prior to being installed in a fishing reel. Therefore, a gap is formed between the bearing receiver of the backstop body and the outer race of the roller bearing, resulting in an idling rotation of the roller bearing when the sleeve is rotated in the normal or reverse direction. Due to the idling rotation of the roller bearing, operation of the reel during jerking motion of a fishing rod is somewhat delayed. Since the roller bearing is fitted into the backstop body prior to being installed in a fishing reel, the typical backstop device cause problems while assembling the fishing reel. Furthermore, the configuration of the outer race of the roller bearing is complicated, so it is very difficult to design such an outer race. Another problem experienced in the typical backstop device is that both the one-way roller bearing and the backstop body are expensive and have to be separately managed by a reel manufacturer, thus increasing the production cost of a fishing reel.